Arvada Concrete Pool Construction

Late March, three warm days after a heavy wet snow. There's a pool-sized hole in a back yard off one of the newer streets, steel tied and waiting, and by Tuesday afternoon there's eight inches of water standing in the deep end that nobody put there.

That's not a disaster. It's information, and it arrives at the only time of year that gives it to you honestly. Everything we do on a concrete pool here is arranged around water: where it comes from, where it goes, and what it's doing to the ground while the shell is young. Get that part right and the rest of a pool build is just sequence.

What a wet March tells us about your lot

Water in an open excavation comes from three places and none of them behave alike. Surface runoff arrives fast and leaves fast, which mostly means the yard slopes toward the hole. Perched water sits on a tight clay layer and shows up days after a melt, usually along one wall at a consistent height. A real water table is the rare one, steady and unbothered by weather, and it changes the design.

We want to know which you have before a shell goes in, because an empty concrete pool with water behind it is a boat. Hydrostatic pressure doesn't care how thick the walls are. It pushes on the floor, and with no way to relieve it, it wins. That's the job of a relief valve, a drained gravel envelope, and a sump we can reach.

West of town there's a second question, since that ground was cut and filled before the houses arrived. Our engineer looks at what the shell will bear on, and where placed fill runs deep the design changes rather than the hope.

An open hole through a Front Range year

Sprayed or formed, and why almost every shell here is sprayed

Shotcrete is concrete driven through a nozzle at high velocity into the steel cage. It compacts itself on impact, takes whatever shape the excavation and the rebar give it, and needs no forms on the wet side. For a curved shell with benches, steps, and a drop into a deep end, that isn't just cheaper. It's the only sane way to build the geometry.

Cast-in-place still has its lane: straight walls, square corners, a plunge pool or a formal spa, or a shell that shares a wall with a structure and needs a formed face on both sides. Genuinely rectilinear designs get a flatter wall out of forms.

Either way the steel schedule comes from our engineer, not a rule of thumb. Bar size, spacing, laps, and how the floor ties into the walls all get drawn, and the cage gets checked before anything is placed. Concrete is the visible part. Steel does the work.

We shot a shell on a Thursday and the forecast turned overnight. Crew was back at six with hoses and blankets. Cure doesn't take weekends off, and neither does the weather.Straight from the crew

What our concrete scope covers on a pool

• Excavation and over-dig, spoil staged for backfill or hauled off
• Engineered steel cage, tied, chaired, and checked before placement
• Plumbing held under pressure through the shoot so a nicked line shows itself immediately
• Shotcrete placed and cut to profile, benches and steps shaped by hand
• Hydrostatic relief in the floor and a drained gravel envelope where water demands it
• Wet cure through the first week, whatever the sky and the calendar are doing
• Coordination with the plaster, tile, and equipment trades so nobody waits on us

Curing a shell in Colorado air

This is where pools get won or lost, and it's the least photogenic part of the job. Fresh shotcrete up here fights thin dry air, hard sun, and wind that pulls water out of a surface faster than the concrete can use it. A shell that dries instead of curing ends up with a chalky face the plaster crew has to fight later.

So we wet it. Several times a day for the first week, longer through a hot dry stretch, crew back on weekends. Skipping it is the most common reason an otherwise good shell disappoints.

Scheduling follows. Break ground in spring and you swim by midsummer. Break ground in September and you get a cured shell before winter with finish work landing in spring, which is a fine plan as long as nobody promised an October swim. What we won't do is leave a fresh shell to take its first freeze unprotected.